Glass-ionomer cements (GICs) are known to be useful as dental restorative materials. GICs are formed from glass ionomer powders which comprise finely ground ceramic powders, the main components of which are silica (SiO2), alumina (Al2O3) and calcium fluoride (CaF2) as flux, sodium fluoride (NaF) and cryolite (Na3AlF6) or aluminum phosphate (AlPO4). Phosphate and fluoride salts are used to modify and control the setting characteristics of the cement. GICs are, in general, formed predominantly from alumina and silica, which form the back-bone of the glass. Glass-ionomer cements are formed by the reaction of an ion-leachable alumino-silicate glass powder with an aqueous solution of polyacid such as polyacrylic acid (polyalkenoic acid). GICs are well-known for their properties of direct adhesion to tooth structure and base metals; for anti cariogenicity due to release of fluoride; low shrinkage resulting in minimized microleakage at the tooth-enamel interface; biological compatibility and low cytotoxicity.
However, conventional GICs suffer from a number of disadvantages such as lack of re-mineralization properties, low bond strength to tooth structure, long setting time, brittleness, poor compressive strength and poor fracture resistance, all of which limit their utility. Consequently, there is a need to improve the biological and physical properties of glass ionomer cements (GICs).